<span>Genetic variation can be caused by mutation (which can
create entirely new alleles in a population), random mating, random
fertilization, and recombination between homologous chromosomes during
meiosis (which reshuffles alleles within an organism's offspring)</span>
Lipid Bilayer.A plasma membrane is made up of Lipid Bilayers, which consists of polar phosphate heads, which are hydrophilic or water loving, and non-polar fatty acid tails, which are hydrophobic. Proteins are embedded in the membrane as well.Cell membranes are known to have holes, or selective permeable.
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Answer:
A) 1000
Most viruses are 1000 times smaller than the average cell